1. Field of Invention
The invention relates to a shredder and, in particular, to an emergency stop switch (ESS) that can immediately stop the operation of shredder to prevent serious injuries.
2. Related Art
To prevent such documents as legal files, receipts, invoices, credit card numbers, research reports, or personal financial information (e.g., credit card and phone bills) from being released, it is common to destroy them using a shredder. Therefore, the shredder has become an indispensable device for both business and home applications.
As is well known, the action principle of a shredder for shredding paper is to dispose several cutting blades on two rotary shafts with spacers in between. A motor and a gear box are employed to drive the two parallel rotary shafts that rotate in opposite directions. They provide a shearing force on passing paper to cut it into small stripes. According to the mechanical cutting type, shredders can be classified as stripe-cut shredders and cross-cut shredders. In the former case, the cutting blades are disposed regularly on the rotary shafts and cut the paper along the longitudinal direction into long stripes. Each blade in the latter case has several hook-shaped cutting edges. The blades are disposed in a spiral way on the rotary shafts. In this case, the paper is not only cut along the longitudinal direction into stripes, but also cut in the transverse direction into chips.
The panel of a conventional shredder is usually provided with an on/off switch. The user can use his/her finger to push the switch so that the shredder operates among the auto, off, and rev modes. The shredder is normally in the auto mode for the user's convenience to insert paper for shredding. However, when the shredder encounters an emergency and has to stop immediately in the auto mode, the user has to switch to the off mode. Even though the switch is clearly marked with the off, auto, and rev modes, it is sometimes too urgent so that the user cannot react correctly and put the shredder in the off mode. This often results in injuries.